Louis lynn white



(No Model.)

L. L. WHITE.

MOLD FOR SHAPING METALLIC TOOTH GROWNS.

No. 571,102. 7 Patented Nov. 10,1896.

5 mm or 'oiwaf UNITED STATES PATENT OFFIC LOUIS LYNN WHITE, OF OAKLAND,CALIFORNIA, ASSIGNOR OF ONE-HALF TO WALTER F. LEWIS, OF SAME PLACE.

MOLD FOR SHAPING METALLIC TOOTH-CROWNS.

SPEGIFIGATIONformingpart of Letters Patent No. 571,102, dated November10, 1896.

Application filed February 25, 1896. Serial No. 580,730. (No model.)

To all whom it may concern.-

Be it known that I, LOUIS LYNN WHITE, a citizen of the United States,residing at Oakland, county of Alameda, State of California, haveinvented an Improvement in Molds for Shaping Metallic Tooth- Crowns andI hereby declare the following to be a full, clear, and exactdescription of the same.

My invention relates to the class of apparatus for making metallicseamless toothcrowns; and it consists in anovel mold, which I shallhereinafter fully describe and claim, and the purpose of which is toreduce to final and perfect shape the metallic crown.

The object of the invention is to provide a means by which this finalshaping of the tooth-crown shall be rendered accurate and easy ofaccomplishment.

Referring to the accompanying drawings, Figure 1 is a vertical sectionof my mold. Fig. 2 is a View showing the means for obtaining a plastermatrix from a plaster tooth. Fig. 3 is a View of the plaster matrix.Fig. 4 is a view of the metallic die formed in matrix, Fig. 3. Fig. 5shows the swaging of the cap on the block J. Fig. 6 is a view of thecompleted or shaped crown.

The mold consists of a casing or shell formed of a base-section A,having a central hole a and an uprising peripheral flange a and a topsection B, having a central conical opening or hole b, the taper ofwhich is from above downwardly, so that the wider part of the opening isat the top and the narrow below, and said section has on its bottom acircumferential rabbet b, which is adapted to fit the flange a of thelower section, so that the two sections fit accurately together and areflush peripherally and may be readily placed and removed. When together,the conical hole I) of the upper section is alined with the central holea of the lower section. A removable core C completes the mold. This ismade of lead or other soft metal or alloy, said core being made conicaland adapted to fit within the conical hole I) of the upper section B ofthe mold, and said core having a central hole 0 and its body madereadily separable into halves in any suitable manner. These partsconstitute the mold; but in order to understand their operation it willbe necessary to recite briefly the steps of the operation prior to andleading up to the use of said mold. This description of the prior stepsI deem it best to accompany with illustration s, whereby they may bereadily understood.

A cast is first taken of the tooth to which the crown is to be applied.This cast I make in plaster in the usual manner, and from it, as amatrix, I make a plaster die D, repre senting the tooth. This die I thentake and place it, as is shown, half embedded in a plastic material,such as putty E, in a frame F. The other half of thisframe I then fillwith plaster, the plaster die being previously varnished, so that I thusget in the plaster the impression of one half the die D. I then removethe putty and substitute in its place plaster, which will thus take theimpression of the other half of the die D, and then, upon removing theplaster with its confined die from the frame and immersing them in hotwater, so that the varnish will soften,I am able to separate the halvesof the plaster cast thus formed, and thus obtain a cast or matrix suchas represented by G. I now fill this cast (the plaster die or tooth Dbeing'removed) with a metallic alloy, and upon separating the cast Iobtain the metallic die H, which represents the tooth to be crowned. NowI take a disk of gold and by means common in the art force it throughsuccessive holes of a die? plate, said holes having gradually-decreasingdiameters, until I obtain a cup-shaped piece or cap, such as I,approximating in its interior capacity the exterior of the metallic die.I-I. Then this cap I is fitted to the metallic die H and is swaged uponthe top of a block of lead, such as J, in order to form the cusps, andit is further manipulated by mild hammering to reduce and round theedges of its grinding-surface. It is at this point that the use of mymold begins.

The central core 0 is placed within the conical hole I) of themold-section B, and the me-' tallic die 11, with the metallic capI stillfitted upon it, is inserted in the hole a of the core, and by thepressure and force of a hammer and hand-bar said die and cap are forceddown into the core, and by this forcing and the pressure of the core thecap is accurately molded or shaped to the metallic die over which itfits.

The lead core is sufficiently soft or yielding to provide the necessarypressure as the force is applied to bear the metallic die down into it.Being of a yielding nature, the metal of the core pressed downwardlybefore the entering die and cap finds relief in the hole of thebase-section. Then the shaping is complete,- the two sections A and Bare separated and the core is removed from the upper section, and being,as before stated, readily separable it is divided, and the nowprefectly-shaped crown, with the die over which it fits, is removed andthe crown is then taken from the die. The removal of the crown from thedie'is readily effected by means of heat, as the die is'fusible at amuch lower temperature than thegold and is simply melted out. lVhateverparticlesof baser metal still adhere to the gold are removed bytreatment with nitricacid.

The core 0 may be madereadily'separable in various ways,.and theway'ldeem practical is merely, after-it is formedvin a single piece, tocut itapart and then hammer it together to -a certain extent, so that whileacting. firmly as a single piece again it can be readily split. Thismold insures accuracy and precision in the shapingof the seamlessmetallic crown, and the operation canbe readily carried out.

Having thusdescribed' my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. A mold for shaping seamless metallic tooth-crowns, consisting of acasing: or shell and a core of soft'metal seated in said shell landhaving a receiving-hole for the metallic die and its fitted: metalliccap to be shaped into the crown.

2. A mold for shaping seamless metallic tooth-crowns, consisting of acasing or shell,

and a core of soft metal readily separable into to and having a conicalhole, the lower end of which alines with the hole in the lower section,and a core of soft metal having a conical shape to fit in the conicalhole of the upper sectionof the casing'or shell, and a central holetoreceive the metallicdie with its'metallic cap to be shapedintothe'crown.

4 A mold for shaping metallic seamless tooth-crowns,.consisting'of acasing or shell formed of a centrally-perforated lower secvtion, anupper section fitted removably thereto and having.a conical'holealiningwith the holeof the lower section, and a core of soft metal formedin.readily-separable sections and fittingin the conical hole of theupper section of thecasing or shell, said core having a hole tore'ceivethe metallic die withlitsmetallic cap to be shaped into thecrown.

In witnesswhereofl have hereunto set my hand.

LOUIS LYNN WHITE. \Vitnesses':

RUssELL IL Goon, WVALTER' F. LEWIS.-

